Lifting-jack.



P. L. GORMLEY.

LIFTING JACK.

APPLICATION FILED Nov. 27, 1908.

Patented May 11, 1909.

WibsSes:

lwenor." Frankl. Gormle FRANK L. GORMLEY, F BOSTON, MASSACHUSETTS.

LIFTNG-J'ACK.

Application filed November 27, 1908.

Specification of Letters Patent.

Patented May 11, 1909` Serial No. 464,787.

To all whom t may concern:

Be it known that I, FRANK L. GonMLnY, a citizen of the United States of America, and a resident of Boston, in the county of Suffolk and State of Massachusetts, have invented certain new and useful-Improvements in Lifting-Jacks, ofwhich the following is a specification.

This invention relates to lifting jacks and particularly to that class of acks which are known as ratchet screw jacks, and has for its Object the provision of a means whereby the movable member is prevented from being accidentally lowered under a heavy load.

The invention consists in providing a nut, which is preferably divided, with some means, as, for instance, a wedge-shaped shoulder, which, when the movable member of the jack to which the screw is secured is subjected to any weight, will force the nut into firm Contact with the threads of tl e screw and prevent the screw from turning in said nut, except when power is applied to the screw itself to cause a rotation thereof.

The invention consists in certain novel features of construction and arrangement of parts which will be readily understood by reference to the description `of the drawings and to the claims hereinafter given.

0f the drawings: Figure 1 represents a horizontal section of a lifting ack embodying the features of this invention, the cutting plane being on line 1-1 on Fig. 2. Fig. 2 represents a vertical section of the same, the cutting plane being on line 2-2 on Fig. 1. Fig. 3 represents a section of the device for rotating the screw, the section being on line 3 3 on Fig. 1. Fig. 4 represents a horizontal section of the jaclnrthe cutting plane being on line 4 4 on Fig. 2, and Figs. 5 and 3 represent, respectively, a plan and an elevation of the divided nut.

Similar characters designate like parts throughout the several 'figures of the drawings.

In the drawings,10 represents a suitable base supporting a stationar r standard 11 over the outer peripheryof which is iitted a movable sleeve 12 to the upper end of which is threaded ahead 13. ln the upper inner end of the head 13 is mounted a plate provided with an annular groove 15 and a central bearing for the reduced shank 16 of the revoluble threaded member or screw 17.

Keyed to the reduced shank 16 of the screw 17 is a gear 18 meshing with a gear 19 formed upon or secured to a revoluble shaft 20 mounted in a lateral bearing 21 formed upon the plate 22 secured to the head 13. The gear 13 is provided with an annular groove 15* corresponding to the groove 15 and in these grooves 15 and 15* are placed a plurality of balls 18A* to reduce the friction.

Gn the reduced end ofthe shaft 20 is keyed or otherwise secured a ratchet 23 between the two arms 24 of a bifurcated member 25. This bifurcated member 25 is provided with an operating handle 26 and in ears 27 formed u on the arms 24 is'secured a pin 28 u on wiich is mounted the double acting paw 29, one of the teeth of which is retained in engagement with the teeth of the ratchet 23 by means of the locking bolt 30 mounted in a socket in the member 25 and forced outwardly by means of the spring 31. The bolt 30 is prevented from turning by means of the screw 32 engaging a longitudinal slot in the bolt .3G as indicated in 3 and the outer end of said bolt is Veshaped so that the point thereof will engage either the face 33 of the pawl 29 to cause one of the teeth thereof to engage with the `ratchet wheel 23 or with the face 34 to cause the other tooth of the pawl to engage with said ratchet wheel, the particular tooth to be engaged with the ratchet wheel 23 being determined by the direction in which it is desired that the gear 19 shall be turned. it is obvious that by giving the handle 26 an up-and-down or pump handle motion with the pawl 29 in the position shouni in Fig; 3, the gears 18 and 19 will be rotated so as to cause'the screw 17 to turn within the nut 35 to cause a lifting of the head 13 relative to the standard 11. it is also obvious that when the position of the double-acting pawl 29 is reversed and the il-shaped end of the locking bolt 13 is in en- Y gagement with the face 34 of said pawl and the same motion is accorded to the handle 26, a reverse motion will be accorded to the gears 13 and 19 and the screw 17 will be turned in its nut 35 to cause a lowering of the head 13.

The jack thus far described is of wellknewn construction and forms no part of the present invention. lt has been found, howL ever, that when the threads of the screw 17 are of a certain coarse pitch and thel head 13 is subjected to the Weight of a .heavy load, i in the nut ing et the i ylhis acei.- g

sometimes the screw 17 will tur 35 and cause the accidentallowe. head relative to the standard. ll..

dental lowering ot the lifting jack under a under a heavy load the nut 35 is divided as indicated in Figs. 4l and 5, at 56, While tire outer periphery ot said nut is provided With conical shaged cam shoulder 37 this shtmlk der 37 normally resting upon the inclined tace ol' the upper end of a ring 3&5 in a socket 39 in the upper end of the standard. ll.

Each of the parte oi the divided. nut 535 is lprovided with slots fl() out inte the periphery and extending loiiigitudinally thereof to its upper end. The soclet 3l) has similar slots cut into the upper end olj the fan dard il. and into these slots are inserted keys el, each ci which is halt embedded in tl e slot in the standard. li While the other 'ia l is in one of the slots l() ci the nut 35. llhese lm will prevent the nut from tu.:I ing during the rotation of the screw l?" While at the saine time the two parte ol the nut are tree to move endWise or longitudinally of the axis olf the screw 1.7. rlllneaded to the upper end ol the standard 1?.. is a cup-shaned member 142 Which extends over the nut 235 and the 1rie/ys lll and prevents them from becoming displaced.

ln the olneration olA the invention the shoulder 37 of t ie tvvo p arts of the nut 35 normally rests upon the upper end ot the ring 3S and When the handle 2o is operated the screvT l? may be rotated in the nut 85 in either direction to cause a lifting or lowering of the head i3. Should, however, the head "f l subjected to a heavy load the Weight of which is suicient to cause a tendency ot the screvT if? j to accidentally rotate .in the nut 35, the

downward pressure of the screw upon the tWo arts of the nut 35 will cause the inclined shou der 37 to so act upon the upper ends el.Z the ring 38 to force these two parts toward eac-h other and to be tightly clamped upon the screw 17 so that it Would be impossible i f for the screw to turn therein, thereby abso lutely preventing the accidental lowering of the head under a heavy load. Should it be desired to lower the load, the position ot the paWl 29 is reversed and the screw i7 is rc tated in the nut 35 in the opposite direction l i stalron-ary member "provided with a wedge by means ol the handle is soon as the head. has been lowered a desired distance and the operation of the handle 26 has ceased the nut 35 Will immediately again clamp the screw 17 and prevent any accidental rotation thereof.

4lt is believed the operation and many adstationary member;

der a load to clamp said s 'l"2. "Y 1,.. l Y 3. lu a uiting iam., the combina and nie an operable unnut upon s 'd screw. tion olf' a stationary member; a movable memlicr v.' lor said movable member aid screw; a divided nut iinxniber; and i' sans opl lo clamp said. nut upon means :in said statmi'n.'l erable 'Lu l` n. ln a lifting fiaclr., the combination ol. a nary member; a movable member thereon; a screw tor said .inovalfil e member; means lor rotating said screw; a nut in said stationary member ha ing a cam-shaped shoulder; and a ring surrounding said nut ated. te act on said shouldi-.u' to clamp ,nur upon said screw when said nut is ected to doe'nward i fessure ln a lifting jack, the combination ol a in nber; a movable niienibcu' hercon; frevf lor said movable member; means lier rotating said screw; a divided nut in said stationary member having a camm slapcd shoulder; and a ring surroimding said uut andv adairited to act on said shoulder to clan'ip saidA nut unen said screw when said nut is su lect .il to downward pressure,

5. fin a int-ing llach, the combination of a stationarjvT member, a movable member tl'iereon; a screw for said movable member g means for rotating said. screw; nut in said stationary member .having a cannshaped sliimilder; a ring surrounding said nut and adapted to act on said slioulder to clamp said lupon said screw when said nut is subdoWnWard pressure 5 and means for n ting the rotation ol said nut and ring. e. iu a lifting jack, the combination ol a stationary member; a movable member thereon, a screw lfor said movable member, as `lor rotating said screw, a nut in said ary member having a cam-shal'ied a ring surroun-ding said nut and with a rvedge-sl'iapcd odge adapted said shoulder to clamp said nut scV when said nut is subjected v-vard pressure 5 and means for Aprej the rotation ot said nut and ring.

a lifting ja ii, the combination ol a .il a movable member thereon; a screw tor said movable member, a nut there lll() mitting the end movement thereof under a load to clamp said nut on said screw.

8. In a lifting jack, the combination of stationary member provided with a Wedge shoulder; a movable member thereon; ra screw for said movable member; a divided nut therefor in said stationary member provided With a cam-shaped should er normally resting on said Wedge shoulder; and means for preventing said nut from rotating' While 'permitting the end movement thereof under a load to Clamp said nut on said soreva 9. ln a lifting jack, the Combination of a stationary member' provided with a wedge shoulder; a movable member thereon; a screw for said movable member; a nut therefor in said stationary member provided with a cam-shaped shoulder normally restingl on said Wedge shoulder and havingI slots eX- tendingl longitudinally oi' its periphery; and keys mounted in said stationary member and extending into said slots.

10. ln a lifting' jack, the Combination of a stationary member provided with a Wedge shoulder; a movable member thereon; a screw for said movable member; a nut therefor in. said stationary member provided with a Gam-shaped shoulder normally resting on said Wedge shoulder and having slots eX- tending` longitudinally of its periphery keys mounted in said station ary member and eX- tendin@ into said slots; and a cap threaded to the upper end of said stationary member to prevent the displacement of said keys, and the up xvard movement of said nut.

11. The combination of a stationary member; a nut in said stationary member; a revoluble screw in said nut; a movable member supported by said screw; and means operable under a load to clamp said nut upon said screw.

12. The combination of a stationary member; a divided nut in said stationary member; a revoluble screw in said nut; a movable member supported by said screw; and means operable under a load to clamp said nut upon said screw.

i3 The combination of a stationary member; a divided nut in said stationary member having` a cam shoulder; a revoluble screw in said nut; a movable member supported by said screw; and a ring surrounding said nut and adapted to not on said shoulder to clamp said nut upon said. screw when said nut is subjeeted to downward pressure. l

lll. The combination of a stationary member; a divided nut in said stationary member having' a cam shoulder; a revoluble screw in said nut; a movable member supported by said sorevv; a ringl surrounding said nut and adapted to aet on said shoulder to Clamp said uut upon said screw when said nut is subjected to downward pressure; and means for prevei'iting the rotation of said nut and ring.

Sigi'ied by me at -l Post @Hice Sq., Boston.7 Mass.VY this 24th day of' November7 1908.

FRANK L. GORMLEY.

Witnesses VVTALTER LOMBARD; NATHAN C. LOMBARD. 

